'use strict';
function rank_by_two_large_one_small(collection){
  //这里写代码。。。
  let arr=collection.sort(function(a, b) {
    return a - b;
  });
  let arr1=arr.slice(0,3);
  let num1=arr1.shift();
  arr1.push(num1);
  let arr2=arr.slice(3,6);
  let num2=arr2.shift();
  arr2.push(num2);
  let arr3=arr.slice(6);
 

  return arr1.concat(arr2,arr3);




}
module.exports = rank_by_two_large_one_small;
